Modern 3D computer graphic applications require the manipulation, storage and transmission of increasingly complex geometries. Efficient manipulation of such data is critical for the implementation of high performance graphic systems.
Traditionally, complex geometries have been represented as polygonal meshes and parametric surfaces patches such as NURBS. While polygonal meshes are simple to process, they don't constitute a particularly compact representation for a complex, natural surface. Indeed, representing complicated objects might require a large number of polygons. Parametric surfaces obviate most of these disadvantages, but are much harder to render.
Accordingly, many schemes for compact representation of complex geometries have been presented by various authors. An example can be found in Deering M., "Geometry Compression", Computer Graphics (proc. SIGGRAPH), pages 13-20, August 1995 where a method for compressing geometries and associated information (such as normals and colours) is presented. Deering is directed to real time rendering. Methods to efficiently convert existing models in the format described in Deering can be found in Chow M., "Optimized Geometry Compression for Real-time Rendering" (proc. IEEE Visualization '97), 1997.
A different approach is taken in DeRose T. "Multiresolution Surfaces for Compression, Display, and Editing", SIGGRAPH '96 Course Notes, Course Number 13, Wavelets in Computer Graphics, where a multiresolution representation of geometric data is described along with its advantages for compression.
Other approaches, such Hoppe H., "Progressive meshes", Computer Graphics (proc. SIGGRAPH '96), pages 99-108, 1996 and Hoppe H., Popovic J.; "Progressive Simplicial Complexes", (http://research.microsoft.com/.about.hoppe) 1997 are based on mesh simplification and allow access to the geometric data at different levels of detail. Of course, in all these cases, there is a decompression overhead on the top of the rendering process.